1. Field of the Invention
The present invention relates to health care devices comprising medical and veterinary devices, and more particularly to devices useful in suturing or closing wounds or incisions.
2. Description of the Related Art
The use of surgical staples in the health care field, comprising both the medical and veterinary fields, to close wounds and incisions has begun to, in many contexts, replace conventional suture ligature.
Surgical skin stapling has been found to be desirable in that it requires less skill of the health care clinician than conventional suture ligature. In addition, removal of staples is faster and easier than suture ligature. As in most fields, simplicity in wound and incision closure decreases the possibility of error, an accomplishment of particular importance in the health care field. Surgical stapling also provides better post-surgery aesthetic appearance than does conventional suture ligature and needle wound closure. Further still, postoperative infection is reduced in the use of skin stapling over suture ligature.
Because surgical stapling takes less time than conventional suture ligature, surgical stapling is economically advantageous. Both implanting and removing surgical staples is easier than placing and removing conventional sutures. It is, for example, estimated that the typical surgical stapling operation takes approximately 10% of the time of a conventional ligature placement. Thus, a significant time savings is involved in using surgical staples for wound and incision closure.
However, not all clinicians are able to take advantage of stapling technology because available surgical stapling devices are expensive. For example, clinicians who work in low-income regions or without insurance support, are often unable to afford currently available surgical staple devices and supplies. However, clinicians and their patients who can afford stapling devices end up benefiting economically in the long run.
While advantageous in the respects discussed, current surgical stapling devices present certain limitations. First, surgical stapling devices without a removable cartridge are designed so that the entire stapling device is discarded after all staples have been used. Such stapling devices are not economically advantageous in the long run. Also, because all parts of such a stapling device are disposed of after the staples are used, the quality of the parts must be sacrificed to keep costs down. However, if premium quality components are used, disposing of these parts each time the staples are used raises the cost of using the stapling device.
Current surgical stapling devices which do use a replaceable staple cartridge minimize the waste of many functional components of the stapling device. This recycling of parts for reuse is economically advantageous. However, current surgical stapling devices employing a replaceable cartridge do not allow for reuse of both a staple former and an anvil. Some of the staple cartridges currently in use include both a staple former and an anvil as an integral part of the replaceable cartridge, and all cartridges include at least an anvil or a staple former. By including an anvil and/or a staple former as an integral part of a replaceable cartridge, these components are disposed of with the staple cartridge. Reducing the disposal of functional parts is economically advantageous. Therefore, it is desirable to have a surgical stapling device in which a stapling cartridge does not include either a staple former or an anvil as an integral component of the staple cartridge.
Current surgical staple devices generally provide a feeder shoe to urge a plurality of staples toward the staple-forming or exiting end of the stapling device. A limitation in such feeder shoes and urging mechanisms is that staples are allowed to jam on the sliding surface as the staples move toward the staple-forming or exiting end of the stapling device.
Such staple jams can be at least inconvenient to clinicians who temporarily cannot utilize the stapling device. A limitation in the feeder shoes and urging mechanisms which can lead to staple jams is that while all such feeder shoes contact at least a part of one of the staples, and some feeder shoes contact much of one side of a staple, when a staple slips, the staple can be lodged in spaces either between the staple stack containing a plurality of staples and the track upon which the plurality of staples slide, within other spaces existing within the feeder shoe itself, or between the feeder shoe and the track upon which the staple stack slides. It is therefore desirable to have a staple housing, such as a staple cartridge, in which the outer surfaces of a feeder shoe are continuous with the staple housing and in which the feeder shoe acts as a traveling blocking surface against a fixed blocking surface.
Another limitation of current feeder shoes is that if such feeder shoes are extended completely to the end of the staple cartridge, as when all staples in the staple cartridge have been used so that no staples remain in the staple cartridge, forcing the staple former on the feeder shoe can damage these parts. It is therefore desirable to avoid this force on the feeder shoe and staple former.
Finally, a limitation of current surgical stapling devices is that staples are implanted substantially orthogonal to the skin surface. By inserting staples at an angle of between about 10°–45° relative to the skin surface and then tilting the staple so that the staple is ultimately positioned substantially orthogonal to the skin surface, greater resulting anastomosis can be obtained as the skin grows together. This greater anastomosis allows for shorter healing time. Thus, it is desirable to have a stapling device in which a staple can be inserted at an angle of about 10°–45° relative to the skin, the staple subsequently rotated to a final orientation being substantially orthogonal to the skin's surface.